Portable ramps for pickup trucks are commonly used for loading garden tractors, snowmobiles, all-terrain vehicles and equipment of the like into the box of a pickup truck. It will be appreciated that conscientious users of portable ramps for pickup trucks know that it is preferable to secure the upper ends of the ramp members to the tailgate of the pickup truck in order to prevent accidents that can be caused by the slipping of a ramp member when equipment is being moved thereon.
Various systems have been developed in the past for retaining the upper end of a ramp member to the tailgate of a pickup truck. Some of the devices of the prior art require the use of fasteners through the tailgate. Other models are clamped on to the tailgate or frictionally engaged with the painted surfaces of the tailgate. In general, the use of ramp anchoring devices of the prior art is known to permanently alter to some degrees the visual quality of the tailgate.
Typical devices of the prior art include for example, a ramp system such as the one described in U.S. Pat. No. 3,510,015 issued on May 5, 1970 to Harold L. Roshaven. This ramp system comprises a pair of ramp members having hooks on their upper ends, and a pair of support members having U-shaped straps for retaining the hooks of the ramp members. The support members are clamped onto the tailgate by transversely encircling a major portion of the tailgate.
In other examples, U.S. Pat. No. 3,756,440 issued on Sep. 4, 1973 to joint inventors Gerald G. Raap and Donald F. Kutz describes a pair of ramp members which are pivotally connected to a round bar. The round bar is permanently affixed to the upper edge of the tailgate. U.S. Pat. No. 4,884,838 issued on Dec. 5, 1989 to Frank W. Slater describes another ramp member attached to an elongated cap covering the upper edge of a tailgate. The cap is permanently fastened to the upper edge of the tailgate with screws. U.S. Pat. No. 4,923,360 issued on May 8, 1990 to Phillippe J. Beauchemin illustrates a collapsible tailgate ramp which has an upper end pivotally connected to the upper edge of a tailgate. A last example of a portable tailgate ramp of the prior art is illustrated in Canadian Patent 1,071,811 issued on Feb. 19, 1980 to Lucien Leduc. The ramp described in this document has a pair of pins extending from an upper end thereof. These pins are engageable in corresponding holes through the tailgate.
It will be appreciated that some modem pickup trucks are as luxurious and comfortable as sedan cars. Therefore, a proud owner of a modem pickup truck generally does not want to permanently affix an anchor bar to the tailgate of his/her truck, or to install steel strap members across the painted surface of the tailgate. It is believed that this reality partly explains why the tailgate ramp systems of the prior art in general, have not been broadly used on modern pickup trucks.